I tend to think Worf would have gotten bored as an Ambassador really quickly and found his way back to the action one way or another.
I imagine one day, Worf enters his office to see a stack of paperwork. He works on it for an hour and starts to fidget. Two hours more, the stack is barely half empty. Two hours more, he takes a bat'leth to the stack, marches back into Starfleet HQ and says "I saved the Federation a billion times, make me a Captain".